A little old school but anyone wanting long storing milk (milk?) might think of giving evaporated milk a try. Some people love the stuff. Others can't stand it. It is cheap, typically about $.75 a can, and AFAIK remains at least nominally drinkable as long as the can remains intact. I have used it five, or more, years old and didn't notice any change.

I find it pretty handy for cooking straight as a substitute for cream or mixed with water as milk. Mixed with water kids seem to find it acceptable.